#include <iostream>
#include <iomanip>
using namespace std;

double sqrt_approx(double num) {
    double guess = num / 2.0;
    double accuracy = 0.01;
    while (abs(guess * guess - num) > accuracy) {
        guess = (guess + num / guess) / 2.0;
    }
    return guess;
}

int main() {
    int n;
    cout << "请输入一个正整数 n：";
    cin >> n;
    cout << "平方根的近似值：" << fixed << setprecision(2) << sqrt_approx(n) << endl;
    return 0;
}